The Baggies boss' current deal was due to expire in May at the end of the current Premier League season, but will now stay on in the West Midlands for at least another two years.
Pulis wants to better that achievement this term: "I've said all along that we are in a building phase which requires a step-by-step process".
The deal with the in-game betting specialist will see the West Bromwich-based football club's shirts and training wear sporting the 12BET logo just in time for the 2017/18 season Premier League campaign including Saturday's visit of Bournemouth to The Hawthorns.
Pulis says he is "delighted" to commit to the club following talks with chairman John Williams.
"But I do believe in the future of these young players and that's an important part of the development of the club, especially with the incredible rises we are seeing in prices within the transfer market".
Simon King, chief commercial officer at West Brom, added: "To have been identified as an exciting prospect by the company highlights the growth the club has made globally in recent years".
"Sometimes, for that reason, it makes it hard, yes", he said.
"What I'm finding hard at the moment, and don't get me wrong because I really appreciate it, but at games during pre-season there have been supporters singing "give us a wave" and singing songs". You only have to look at the Championship in recent years to remind yourself how many clubs have fallen through the hoop and how many sets of supporters would love to be where we are now. The Baggies though are expected to hand a debut to summer signing Jay Rodriquez while another new addition, Ahmed Hegazi, is also pushing for a starting berth.